Barington Capital Group is preparing to go to war to split Darden Restaurants.

The activist hedge fund, which last month called for the company to hive off its lower-performing brands, including the Olive Garden and Red Lobster, has hired proxy solicitation firm MacKenzie Partners, indicating that it plans to fight to get its way. The New York-based firm also engaged investment bank Houlihan Lokey to conduct an "independent review" of Darden's operations.

"Although Darden's performance has been disappointing over the past few years, we are convinced that the recommendations we shared with the company's management team in June can meaningfully enhance the long-term profitability of Darden," Barington CEO James Mitarotonda said. Despite the hiring of MacKenzie, The New York Times reports that relations between the hedge fund and Darden remain cordial.

Barington owns a 2.8% stake in Darden. It argues that its proposals, which include focusing on its higher-growth brand and extracting value from its vast real-estate holdings, could boost the company's stock price by 50%.